Reading from a textfile in Java

Question

I am trying to read the following from a textfile

12

650 64 1

16 1024 2

How do I put this in a list or give them variables?

Tried this

class Test{
Scanner lese = new Scanner(new File("regneklynge.txt"));`
ArrayList<String> list = new ArrayList<String>();`
  while (lese.hasNext()){`
    list.add(lese.next());`
  }
}

What have you tried so far? Reading from a file in java is covered basically everywhere. — f1sh, Jan 29 '18 at 10:58
Duplicate of https://stackoverflow.com/questions/5868369/how-to-read-a-large-text-file-line-by-line-using-java — Monkey Supersonic, Jan 29 '18 at 10:58
Possible duplicate of [How to read a large text file line by line using Java?](https://stackoverflow.com/questions/5868369/how-to-read-a-large-text-file-line-by-line-using-java) — Monkey Supersonic, Jan 29 '18 at 10:58
Possible duplicate of [Reading a plain text file in Java](https://stackoverflow.com/questions/4716503/reading-a-plain-text-file-in-java) — Bernhard Barker, Jan 29 '18 at 11:00

peachykeen · Answer 1 · 2018-01-29T11:27:49.433

Check this article our for reading from a file.

Then, you can use Java's Scanner class to read individual items and put them into a list.

For example:

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
import java.util.ArrayList;

public class ReadFromFile {

    public static void main(String[] args) {

        File file = new File("file-name.txt");

        try {

            Scanner scanner = new Scanner(file);

            List<Integer> myIntList = new ArrayList<>(); 
            while (scanner.hasNext()) {
                int i = scanner.nextInt();
                myIntList.add(i);
            }
            scanner.close();
            // now you have an ArrayList with the numbers in it that you can use
        } 
        catch (FileNotFoundException e) {
            e.printStackTrace();
        }
    }
}

Can you post the code that you tried? We would be able to help you much better if you do this. — peachykeen, Jan 29 '18 at 11:04
I updated my answer with an example code snippet. Please see that and tell me if that answers your questions. — peachykeen, Jan 29 '18 at 11:28

Reading from a textfile in Java

1 Answers1